Charging strategies for electric bus fleets: a pathway to grid-friendly and cost-efficient operation

This paper discusses the impact of applying five different charging strategies on power flow and system costs applied on an electric bus fleet in a suburban location using a model-based approach. The bus operation and charging processes were simulated using the open-source software tool SimBA as a case study for a fully electrified bus fleet with battery-electric buses. The flexibility resulting from long standing times in comparison to needed charging times at the bus depots was used to optimize the charging processes with regard to various key performance indicators, such as costs, maximum grid load or evasion of peak load windows. It was shown that by using a combined strategy that minimizes charging power in peak load windows and optimizes charging powers depending on dynamic procurement prices on the energy stock market, power during peak times was reduced by 20% and a cost reduction in electricity and grid related costs by 21% was achieved.